1. Field of the Invention
The present invention relates generally to a mobile communication terminal, and in particular, to a method and apparatus for controlling a Wireless Local Area Network (WLAN) scanning period using a velocity sensor in a mobile communication terminal.
2. Description of the Related Art
The growth of applications requiring increased bandwidths in a mobile communication system, such as a video call and connection to the mobile Internet, is a driving force behind increasing the demand for mobile communication terminals equipped with an Institute Electrical and Electronics Engineers (IEEE) 802.1x WLAN device.
In addition, the functionality of supporting voice call in a cellular terminal using the WLAN device over a WLAN has already been deployed. As a consequence, users can enjoy voice calls with almost the same quality at a low charge rate over the WLAN at places with WLAN Access Points (APs), instead of a cellular network.
In the meantime, along with the development of a velocity sensor for sensing the actions and movements of a user, various applications utilizing velocity sensors are under active development for use in mobile terminals.
The mobile communication terminal may access the WLAN in two ways: manual connection and automatic connection. In the manual connection mode, the mobile communication terminal scans for a neighbor AP to thereby access the WLAN, upon user request, while in the automatic connection mode, the mobile communication terminal periodically scans for a neighbor AP irrespective of the user's request, and when an AP is detected, it automatically connects to the WLAN. In view of the mobility of the mobile communication terminal, when a voice call is placed over the WLAN, handover may occur between a WLAN AP and a cellular network or between WLAN APs. Thus, during the call or during camp-on, the mobile communication terminal needs to scan for a neighbor AP periodically.
However, AP scanning is quite a constraint in terms of current consumption closely related to battery lifetime in the mobile communication terminal, and more current is consumed with a shorter scanning period. If the scanning period is lengthened to reduce current consumption, AP detection takes a long time. Especially in the case of handover to another AP during a call over a wireless network, a time delay occurs to detection of a target AP, thereby significantly decreasing communication quality.